Skull tongs

ABSTRACT

A skull tong is provided for use in applying skeletal traction in treatment of injuries to the cervical spine wherein each of the skull pins is mounted for limited or restricted pivotal movement on an axis generally transverse to the longitudinal axis of the respective skull pins.

United States Patent Crutchfield [451 Apr.11, 1972 [54] SKULL TONGS [72] Inventor: William Gayle Crutchfield, School of Medicine, University of Va., Charlottesville, Va. 22901 [22] Filed: Apr.8, 1970 [21] Appl. No.: 26,535

[52] US. Cl. ..128/84 R [51] Int. Cl. ..A61f 5/04 [58] Field of Search ..128/84 [5 6] References Cited UNITED STATES PATENTS 3,401,688 9/1968 Crutchfield 128/84 Reynolds l 28/ 84 OTHER PUBLICATIONS Multi-Purpose Tongs by W. Reynolds, The Journal Of Bone and Joint Surgery, Vol. 37A, No. 4, July 1955, pp. 866- 870.

Primary Examiner-Richard A. Gaudet Assistant Examiner-J. Yasko Attorney-Stowe" and Stowell [5 7] ABSTRACT A skull tong is provided for use in applying skeletal traction in treatment of injuries to the cervical spine wherein each of the skull pins is mounted for limited or restricted pivotal movement on an axis generally transverse to the longitudinal axis of the respective skull pins.

1 Claims, 7 Drawing Figures PATENTEDAPR 11 1972 3,654,923

sum 1 OF 2 INVENTOR WILLIAM GAYLE CRUTCH FIELD ATTORNEYS PATENTEDAPR 11 I972 SHEET 2 OF 2 FIG.7.

INVENTOR WILLIAM GAYLE CRUTCHFIELD BY ,r/zixw 4/ a ATTORNEYS SKULL TONGS The use of skeletal traction in the treatment of injuries to the cervical spine, in some form or another, has become generally routine with most surgeons and when properly applied, skeletal traction is considered to be the safest, most effective and simplest method of treating patients with acute injuries of the upper spine, as summarized in the article in the Journal of the American Medical Association, May l, 1954, vol. 155, pages 29 through 32, by W. Gayle Crutchfield, and as described and claimed in my US. Pat. No. 3,401,688, dated Sept. 17,1968.

Notwithstanding the wide acceptance of the use of skull tongs in the treatment of injuries to the cervical spine, basically skull tongs are essentially the same as those originally made over 30 years ago and pressure necrosis of the skull has resulted from prolonged traction. To compensate for this it has been necessary to tighten the instrument from time to time and penetration of the inner table of the skull by the skull tong pins, has been a matter of some concern to the profession. In a few instances it has been expedient to replace the skull tong points and to prepare new skull holes when it was necessary to apply traction over an extended period.

It is a primary objective of the present invention to provide a skull tong having all of the benefits of the skull tong described and claimed in my said prior patent, but which is simpler in construction, easier and more convenient to use and which materially reduces puncturing of the skull plate caused by non-uniform or incorrect adjustment of the skull pin mounting elements.

It is a further object of the present invention to provide an improved skull tong which automatically compensates for inaccuracies in locating drill points on the skull of the patient and inaccuracies resulting from skull pin receiving bores having axes which are not equal or radial to the curvature of the skull.

It is another object to provide such a device wherein the major traction applying forces are directed generally normal to the longitudinal axis of the skull tong pins thereby reducing to a minimum puncturing of the skull by the pins.

These and other objectives and advantages of the present invention are provided by a skull tong comprising a pair of generally rigid members, each including end portions and a central or body portion, means pivotally interconnecting the body portions of the rigid members in a scissorslike pivotal arrangement, a pair of skull pin mounting means, means pivotally mounting one of the skull pin mounting means at the extended end of each of the end portions of the generally rigid members, and means associated with each of the integral end portions and each of the skull pin mounting means to positively limit the free pivotal movement thereof.

The invention will be more particularly described in reference to the accompanying drawing wherein:

FIG. I diagrammatically illustrates the use of the improved skull tong in applying traction in the plane of the articulate facets of the cervical spine of a patient;

FIG. 2 is an enlarged plan view of one face of the skull tong shown in FIG. 1;

FIG. 3 is an enlarged perspective view of one of the skull pin mounting means and the means restricting pivotal movement thereof;

FIG. 4 is a fragmentary section substantially on line 44 of FIG. 2;

FIG. 5 is a view similar to that illustrated in FIG. 2 of a modified form of the present invention;

FIG. 6 is an enlarged fragmentary diagrammatic view of one end of the skull tong shown in FIG. 5 illustrating the preferred limit of pivotal movement of the skull pin mounting means; and

FIG. 7 is a perspective view similar to that shown in FIG. 3 of one of the skull pin mounting means of the form of the invention shown in FIG. 5.

Referring to FIGS. 1 through 4 of the drawing, 10 generally designates the improved skull tongs of the present invention.

The skull tongs comprise a pair of members 12 and 14 constructed of relatively rigid generally non-corrodible material which may be sterilized by conventional steam sterilization processes. Steel that is chromium-plated, stainless steel, or stainless steel chromium-plated are examples of suitable construction materials.

Each of members 12 and 14 includes a body portion 16 and a pair of end portions 18 and 20. The end portions 18, in the illustrated form of the invention, are tapered from the body portions 16 and generally rectilinearly aligned therewith; whereas the end portions 20 are tapered from the body portions and are positioned angularly to the body portions.

The body portions are interconnected by a pivot pin 22, which in the illustrated form of the invention, consists of a bolt which is threadedly received in a nut portion 22' and on interval bushing 23 whereby the two members 12 and 14 are mounted for pivotal movement in a scissorslike fashion.

The angular relationship between the ends 20 of members 12 and 14 is such that when the tongs are in use, as illustrated for example in FIG. 2 of the drawing, the longitudinal axes of the members 20 are generally parallel and in spaced relationship.

The extended ends of the end portions 20 of members 12 and 14 are releasably interconnected by means 24 to enable the surgeon to urge the ends of the members 12 and 14 toward and away from each other.

The means 24 comprises a threaded shaft 26 having an unthreaded end 28. The unthreaded end 28 is pivotally mounted in a slot 32 in end element 20 of member 14, by pivot pin 30. End portion 20 of element 12 is also slotted, and opposite faces of the end portion 20 of member 12 are provided with recess portions 34 and 36. Recess 34 is adapted to receive the spherical end portion 38 of a capstan nut 40 which is internally threaded to mate with the threads on the shaft 26. Recess 38 is adapted to receive the spherical portion 42 of a lock nut 44 which also has internal threads which mate with the threads on shaft 26, all as described in my prior patent.

The other extended end 18 of each of the members 12 and 14 pivotally receives skull pin mounting means generally designated 46.

Each of the skull pin receiving members 46 is of generally L-shaped configuration and each includes an end portion 48 which receives, or is shaped to define, a skull pin 50. The skull pins 50 have lower generally cylindrical end portions 52, which terminate in generally conical portions, as more clearly illustrated in FIGS. 3 of the drawing.

At the junction of the two end portions of the L-shaped mounting means 46 is a web 56, which web is received in a slot in its respective end portion 18. A pivot pin 58 pivotally mounts its respective web 56 between the bifurcations of its end member 18. The other extended end 60 of each of the mounting means 46 has permanently secured thereto a stop member 62 which limits pivotal movement of the L-shaped mounting means 46 about pivot pins 58 in one direction of movement. Abutment of surface 64, FIG. 3, with the inner edge 66 of the slot in the end 18 of each arm comprises the pivotal movement stop means in the other direction of movement of each of the L-shaped skull pin mounting members.

In general, the stop member 62 on element 60 and the cooperating edges 64 and 66 are so selected that each skull pin 50 has freedom of pivotal movement of from about 5 to about 15 and preferably about 10. This freedom of movement has been found to fully accomplish the aims, objects and advantages of the present invention.

Referring particularly to FIGS. 1 and 2, the improved skull tong also includes a traction coupling element 68 of generally L-shaped configuration in plan. The L-shaped member 68 includes an end 70 bored as at 72 which receives one end 74 of the flexible draft member 76. The other end of the flexible draft member receives a hooked standard 78 which in turn carries one or more weights 80. The flexible draft member is trained about a pulley 82 whereby the force of the weights 80 applies traction to the body of the patient via the skull tongs 10. The traction force coupling element 68 is bored as at 84 to be slidably received over the bushing or bearing 23 so that even though the clamping screw 22 is cinched the coupling 68 may be freely pivotal relative to the tong.

The coupling element 68 has a foot portion 86 which has a length such that when the element 68 is pivoted as illustrated in phantom lines in FIG. 2 the foot portion 86 provides a convenient measuring device to assist the surgeon when marking the scalp of a patient to locate the points to be bored to eventually receive the extended ends of each of the skull pins.

As illustrated in FIGS. 1 of the drawing, the bores for receiving the pins 50 of the skull clamp are in the plane of the patients spine generally indicated at 86 whereby the traction is properly applied in the plane of the articulating facets, thereby avoiding deformity which may occur in cases where the plane of the traction is anterior of the upper segment of the spine.

In operation of the improved skull tongs of the invention a pair of bores is made in the skull at the proper locations with, for example, a hand drill and drill points provided with stop elements such that the bores formed in the skull are only of a depth to receive the reduced diameter portions of the pins 50. The locking nut 44 and the capstan nut 40 are moved out of engagement with their respective recesses 34 and 36 in the end portion 20 of member 12. The pins are then inserted in their bores, the clamp is tightened to the proper degree by screwing capstan nut 40 inwardly whereby when the hemispherical surface 38 thereof engages its mating detent 34. Since the pins are mounted for limited pivotal movement tightening of the clamps causes the pins to pivot inwardly in the direction of directional arrows A and to thereby cause the points of the pins to be squeezed and hooked into their cooperating bores. Further setting of the pins is not necessary in view of their self aligning and adjusting movement thereof.

A modified form of the improved skull tongs is illustrated in FIGS. 5, 6, and 7 wherein like elements are provided with primed reference characters. The form of the invention shown in FIGS. 5 through 7 differs from the prior described form only primarily in the form of end portions 48. The end portions 48' comprise skull pin mounting blocks 100 which receive skull pins 50 having insertion points 52.

The mounting block 100 has a lateral wing portion 102 which is bored as at 104 to correspond with a mating bore in each of end portions 18 of each arm 14 and 16 of the skull tongs The face 106 of wing portion 102 is spaced from bore 104 such that when the elements 48' are mounted in their respective slots 108 in each end 18 the inner wall 110 thereof cooperates with edges 112 and 114 to provide the limit stops for the pivotal movement of each of the mounting means 48 and in turn the skull pins 50'.

This form of the invention accomplishes all of the aims and advantages of the skull tongs shown and described in reference to FIGS. 1 through 4 and the restricted movement of the skull pin mounting elements 48 is selected as previously described to permit about 10 of freedom.

It has been found that with the clamp mounted as described above the pins generally remain tightly in their respective bores. However, if the instrument becomes loose the elements 40 and 42 are turned until a firm grasp is re-established.

From the foregoing description it will be seen that the present invention fully accomplishes the objects and advantages hereinbefore set forth.

I claim:

1. An improved skull tongs comprising a pair of generally rigid main members, each of said main members including a central body portion and an integral first and second end portion, pivot means pivotally interconnecting the body portions of said main members with the pivot means being normal to the long axes of the main members so as to dispose said main members in a scissors-like arrangement with the first end portions being in generally parallel relation during use of the tongs and with the second end portions being in an outwardly diverging1 relation during such use, means engageable with each of e first end portions of said main mem ers for urging said first end portions toward and away from each other and consequently for moving the second end portions inwardly and outwardly in a complemental curvilinear movement, skull pin mounting members freely pivotally attached to each of the second end portions, pivot pins mounting each of the said pin mounting members on each of the second end portions with said pivot pins having parallel axes that are in parallelism with the pivotal axis of the pivot means between the main members, skull pins carried by and axially projecting from the pin mounting members and arranged so that their longitudinal axes are normal to the pivotal axes of the pivot pins, a traction force attaching means connected to said main members adjacent their first end portions, and fixed, non-adjustable stop means integral with and cooperatively provided on the second end portions of the main members and on the skull pin mounting members at a first fixedly located point above the pivot axes and at a second fixedly located point below the pivot axes of the skull pin mounting members for positively delimiting the free pivotal movement of the skull pin mounting members and the carried skull pins upwardly and downwardly about the pivot axes of the pivot pins in an arc of from about 5 to about 15. 

1. An improved skull tongs comprising a pair of generally rigid main members, each of said main members including a central body portion and an integral first and second end portion, pivot means pivotally interconnecting the body portions of said main members with the pivot means being normal to the long axes of the main members so as to dispose said main members in a scissors-like arrangement with the first end portions being in generally parallel relation during use of the tongs and with the second end portions being in an outwardly diverging relation during such use, means engageable with each of the first end portions of said main members for urging said first end portions toward and away from each other and consequently for moving the second end portions inwardly and outwardly in a complemental curvilinear movement, skull pin mounting members freely pivotally attached to each of the second end portions, pivot pins mounting each of the said pin mounting members on each of the second end portions with said pivot pins having parallel axes that are in parallelism with the pivotal axis of the pivot means between the main members, skull pins carried by and axially projecting from the pin mounting members and arranged so that their longitudinal axes are normal to the pivotal axes of the pivot pins, a traction force attaching means connected to said main members adjacent their first end portions, and fixed, non-adjustable stop means integral with and cooperatively provided on the second end portions of the main members and on the skull pin mounting members at a first fixedly located point above the pivot axes and at a second fixedly located point below the pivot axes of the skull pin mounting members for positively delimiting the free pivotal movement of the skull pin mounting members and the carried skull pins upwardly and downwardly about the pivot axes of the pivot pins in an arc of from about 5* to about 15*. 